 
  
<template>
<div>
    <P>{{ msg }}</P>
    <input type="text" v-model="msg" />
    <ChildCom :title="msg" @change="childChange"/>
</div>

</template>

<script>
import ChildCom from './ChildCom.vue';
    export default{
        data(){
            return{
                msg:"这是父组件"
            }
        },
        components:{
            ChildCom
        },
        methods: {
            childChange(value){
                this.msg = value
            }
        },
    }
</script>